Machine for transversely slotting a strip of concrete pavement at different angles



RETE

May 23, 1967 E. M. TRUELOCK MACHINE FOR TRANSVERSELY SLOTTING A STRIP OFCONC PAVEMENT AT DIFFERENT ANGLES 2 Sheets-Sheet Filed Feb. 4, 1965INVENTOR.

y 23, 1967 E. M. TRUELOCK 3,321,250

MACHINE FOR TRANSVERSELY SLOTTING A STRIP OF CONCRETE PAVEMENT ATDIFFERENT ANGLES Filed Feb. 4, 1965 2 Sheets-Sheet 2 INVENTOR. [6/1/55 M77051064 51/ HAS A 77'0ZA/fl/5' 4452/5, 1756/4 2055a; iii-0v UnitedStates Patent MACHINE FOR TRANSVERSELY SLDTTING A STRIP 0F CONCRETEPAVEMENT AT DIF- FERENT ANGLES Elmer M. Truelock, Albuquerque, N. Mex.,assiguor to Concut, Inc., El Monte, Calif, a corporation of CaliforniaFiled Feb. 4, 1965, Ser. No. 430,353 1 Claim. (Cl. 299-39) The presentinvention relates in general to a machine for grooving or slottingpavement and, more particularly, to a machine for transversely slottinga strip of concrete pavement at longitudinally spaced points to providecontraction joints at such points.

It is conventional in present-day concrete highway construction to pourthe concrete in long strips Without transverse joints. After theconcrete of a particular strip of pavement has set sufiiciently,transverse grooves or slots are cut therein at longitudinally spacedpoints, the depth of out being but a fraction of the thickness of thepavement. Subsequent contraction of the pavement results in controlledtransverse cracking of the strip along the transverse slots, therebyproviding the necessary contraction joints in a regular pattern.

When a strip of concrete pavement having transverse contraction jointsis in use, vehicle wheels crossing the joints impose shock loads on thesucceeding slabs, such shock loads being extremely severe in the case ofheavy vehicles such as heavy trucks, large aircraft, and the like. Inorder to reduce the impact of vehicle wheels crossing contraction jointsin pavement, it is necessary to form the joints at an angle to the pathof vehicles crossing the joints which differs susbtantially from 90. Byproper selection of the angle of such a nonperpendicular joint, only onewheel of a pair of laterally-aligned vehicle wheels will cross the jointat a time. Consequently, the impact load produced by a vehicle crossingsuch a nonperpendicular joint is only half the impact load imposed witha perpendicular joint.

The basic object of the invention is to provide a machine fortransversely slotting a strip of pavement having very simple means forobtaining a nonperpendicular slot orientation, or any desired slotorientation.

In general, the invention contemplates a cross slotting machine whichincludes a wheeled vehicle movable longitudinally of the strip ofpavement and having a frame supported by longitudinally-spaced front andrear wheel assemblies, and which includes pavement slotting means,

movable laterally of the frame along a transverse slotting path, fortransversely slotting the strip of pavement while the vehicle isstationary.

An important object of the invention is to mount the wheel assemblies onthe frame for pivotal movement relative to the frame about upright axesso as to vary the angle of the transverse slotting path relative to thelongitudinal path of movement of the vehicle along the strip ofpavement. With this construction, any desired cross slot angle relativeto the strip of pavement can be achieved merely by correspondinglyadjusting the angular positions of the wheel assemblies relative to theframe and then orienting the wheel assemblies parallel to thelongitudinal edges of the strip, which is an important feature of theinvention.

Another object of the invention is to provide mounting means for thewheel assemblies comprising upper bearing plates on the frame resting onlower bearing plates on the wheel assemblies and pivotally connectedthereto by upright pivot pins, the wheel assemblies being pivotablerelative to the frame into the desired angular positions about the axesof such pivot pins.

Still another object is to provide means extending 3 ,321,250 PatentedMay 23, 1967 through the upper and lower bearing plates associated withthe respective wheel assemblies for locking such wheel assemblies in thedesired angular positions.

Preferably, the frame of the wheeled vehicle is supported by front andrear pairs of laterally or transversely spaced wheel assemblies, thefront and rear pairs being spaced apart longitudinally of the vehicle.An object in this connection is to provide the wheel assemblie of one ofthe pairs, preferably the rear wheel assemblies, with driving wheels,and to provide means for driving such wheels to advance the vehiclelongitudinally of the strip of pavement from one cross slotting locationto the next.

Another object of the invention is to provide means for rotating thedriving Wheels which includes a differential on the frame in a laterallyintermediate position, and which includes driving connections betweenthe differential and the driving wheels, such driving connectionsincluding universal and slip joints to permit pivoting of thecorresponding wheel assemblies relative to the frame.

Another object is to provide means for braking the Wheels of one pair ofwheel assemblies, preferably the driving wheels, to lock the vehicle inposition at each cross slotting location. A related object is to provideseparately-actuable braking means for the wheels of the twobrake-equipped wheel assemblies to permit steering of the vehicle alongthe strip of pavement. Still another object in this connection is toprovide a machine wherein the two braking means act on the drivingconnections between the differential and the wheels of the driving wheelassemblies.

An important advantage of the particular means of the present inventionfor varying the angle of the transverse slotting path relative to thelongitudinal path of movement of the vehicle is that it permits the useof a frame having a longitudinal dimension which is small compared toits lateral dimension. Thus, when the machine is loaded on a trailer,for example, with its longitudinal dimension perpendicular to thelongitudinal axis of the trailer, the over-all width of the resultingload is minimized so that the machine can be transported long distanceswithout exceeding maximum width limits. Also, if it is desired totransport the machine of the invention a relatively short distance underits own power, the Wheel assemblies can readily be oriented parallel tothe longitudinal axis of the frame to make driving the machine moreconvenient to the operator. Further, with the wheel assemblies orientedparallel to the longitudinal axis of the frame, the lateral dimension ofthe frame is minimized to permit passagethrough spaces which would notbe wide enough to permit passage if the wheel assemblies were orientedat angles to the longitudinal axis of the frame.

The foregoing objects, advantages, features and results of the presentinvention, together with various other objects, advantages, features andresults thereof which will be evident to those skilled in the art towhich the invention relates in the light of this disclosure, may beachieved with the exemplary embodiment of the invention described indetail hereinafter and illustrated in the accompanying drawings, inwhich:

FIG. 1 is a plan View of a machine of the invention for transverselyslotting a strip of pavement, the machine being shown adjusted to cut anonperpendicular slot in a strip of pavement;

FIG. 2 is a side elevational view showing the lefthand side of themachine of FIG. 1, except that the machine is adjusted to make aperpendicular cut in the strip of pavement;

FIG. 3 is a fragmentary rear elevational view, taken as indicated by thearrowed line 33 of FIG. 2; and

FIGS. 4 and 5 are enlarged, fragmentary sectional views 3 respectivelytaken along the arrowed lines 4-4 and 5-5 of FIG. 2 of the drawings.

Referring particularly to FIG. 1 of the drawings, the cross slottingmachine of the invention is designated generally by the numeral andcomprises a wheeled vehicle 12 supported by and movable longitudinallyalong a strip of concrete pavement 14, the function of the machine beingto cut longitudinally spaced, transverse slots 16 in the pavement stripat an angle relative to the longitudinal edges of the strip differingsubstantially from 90. The wheeled vehicle 12 comprises a frame 18supported by laterally-spaced front wheel assemblies 20 andlaterally-spaced rear wheel assemblies 22, the latter being spacedlongitudinally from the front wheel assemblies. The machine 10 furtherincludes pavement slotting means 24 for cutting successivenonperpendicular transverse slots 16 at successive longitudinalpositions of the machine along the pavement strip 14. The slotting means24 is carried by the frame 18 of the wheeled vehicle 12 longitudinallyintermediate the front and rear 'wheel assemblies 20 and 22, and ismovable laterally of the frame, in a manner to be described, in thecourse of cutting each transverse slot 16 while the vehicle 12 remainsstationary.

As will be described in more detail hereinafter, the wheel assemblies 20and 22 are pivotable relative to the frame 18 about upright axes to varythe angle between the longitudinal centerline 26 of the frame and thelongitudinal edges of the pavement strip 14. Thus, when the wheelassemblies 20 and 22 are oriented parallel to the longitudinal edges ofthe pavement strip 14, as shown in FIG. 1, the slotting means 24 cutsthe transverse slots 16 at a corresponding angle to the longitudinaledges of the pavement strip. If desired, a transverse slot 28, FIG. 2,which is perpendicular to the longitudinal edges of the pavement strip14 may be produced by pivoting the wheel assemblies 20 and 22 relativeto the frame 18 until they are oriented parallel to the longitudinalcenterline 26 of the frame, and by reorienting the machine 10 until thewheel assemblies are again oriented parallel to the longitudinal edgesof the pavement strip.

Considering the machine 10 in more detail now, the frame 18 is shown asrectangular and as having a longitudinal dimension, in the direction ofits longitudinal centerline 26, which is relatively small as compared toits lateral dimension or width, the magnitude of the latter beingdetermined by the width of the pavement strip 14. Except as hereinafterpointed out, the frame 18 may be of any suitable construction so that adetailed description is not necessary.

Considering the pavement slotting means 24, it comprises two laterallyspaced slotting units 30 interconnected to move laterally of the frame18 in unison in cutting one of the transverse slots 16. Each slottingunit 30 is similar to the laterally movable slotting unit of the crossslotting machine of Patent No. 2,791,412, issued May 7, 1957, to CecilW. Hatcher, attention being directed thereto for a more completedisclosure. Briefly, each slotting unit 30 comprises a carriage 32supported by rollers 34 movable along tracks 36 extending laterally ofand mounted on the frame 18. Each carriage 32 is guided in its lateralmovement relative to the frame 18 by a guide rail 38 on the frame.

Each slotting unit 30 includes a motor, preferably an internalcombustion engine 40, mounted on the corresponding carriage 32. Alsomounted on each carriage 32 are laterally spaced arbors 42 the axes ofwhich are parallel to the longitudinal centerline 26 of the frame 18.The two arbors 42 on each carriage 32 are driven by the correspondingengine 40 through belts 44, respectively. The four arbors 42 of the twoslotting units 30 respectively carry four rotary slotting elements 46arranged in tandem so that they all cooperate to cut a single transverseslot 16 as the carriages 32 are moved laterally along the tracks 36. -Itwill be understood that the rotary slotting elements 46 on each carriage32 cut slightly more than one-half the length of each transverse slot16, there being sufiicient overlap of the movements of the slottingunits 30 along their transverse slotting path to insure a cut extendingcompletely across the pavement strip 14.

The manner in which the carriages 32 are moved laterally along thetracks 36, the manner in which the rotary slotting elements 46 are movedinto and out of cutting engagement with the pavement strip 14, and thelike, are all disclosed in the aforementioned Hatcher patent.Consequently, a further description herein is not required.

The manner in which the front and rear wheel assemblies 20 and 22 aremounted on the frame 18 for pivotal movement relative thereto aboutupright axes will now be considered. Basically, the mounting means forthe front wheel assemblies 20 respectively comprise front upper bearingplates carried by the frame 18 adjacent the front corners thereof andresting on front lower bearing plates 52 forming parts of the frontwheel assemblies 20. Each set of upper and lower bearing plates 50 and52 is pivotally interconnected by an upright pivot pin 54 which permitsthe desired pivotal movement of the corresponding front wheel assembly20 to vary the angular orientation thereof relative to the frame 18.Similarly, the rear wheel assemblies 22 are mounted on the frame 18adjacent the respective rear comers thereof by rear upper bearing plates56 on the frame, rear lower bearing plates 58 on the rear wheelassemblies, and upright pivot pins 60. With this construction, the frontand rear wheel assemblies 20 and 22 may be oriented at any desired anglerelative to the longitudinal centerline 26 of the frame 18.

Each of the front and rear wheel assemblies 20 and 22 is preferablylocked in its desired angular position rela tive to the frame 18 byclamping the corresponding upper and lower bearing plates together withthe correct angular relationship therebetween. Turning to FIG. 4 of thedrawings, four clamping bolts 62 are shown as extending through thecorresponding front upper bearing plate 50 and through arcuate slots 64in the corresponding front lower bearing plate 52, such slots beingconcentric about the axis of the corresponding pivot pin 54. Bytightening nuts, not shown, on the four clamping bolts 62, thecorresponding front wheel assembly 20 can be locked in position with thedesired angular orientation relative to the frame 18. An orienting pin66 may be used to orient the corresponding front wheel assembly 20 atany of several preselected angles relative to the longitudinalcenterline 26 of the frame 18. This orienting pin extends downwardlythrough the corresponding front upper bearing plate 50 and may beinserted into any one of holes 68, 70, 72, 74 and 76 in thecorresponding front lower bearing plate 52. As will be apparent fromFIG. 4 of the drawings, if the orienting pin 66 is inserted into theorienting hole 68, the front wheel assembly 20 in question is orientedparallel to the centerline 26 of the frame 18, in which case theslotting means 24 will cut a transverse slot perpendicular to the edgesof the pavement strip 14. By inserting the orienting pin 66 in either ofthe orienting holes 70 and 72, the transverse slot cut by the slottingmeans 24 will be oriented at an angle a to one side or the other of aperpendicular to the edges of the pavement strip 14. Similarly,inserting the locating pin 66 into either of the orienting holes 74 and76 will result in a deviation of the transverse slot from theperpendicular by an angle [2.

Turning to FIG. 5, the mounting means for each rear wheel assembly 22comprises a similar arrangement of clamping bolts 82, arcuate slots 84in the corresponding rear lower bearing plate 58, orienting pin 86, andorienting holes 88, 90, 92, 94 and 96 in such rear lower bearing plate.As will be apparent, the locating hole 88 produces an orientation forthe corresponding rear wheel assembly 22 such as to produce aperpendicular transverse cut. The orienting holes 90 and 92 produceangular orientations forming transverse cuts which are off perpendicularby the angle a. Use of the orienting holes 94 and 96 provides transversecuts off perpendicular by the angle b.

It will be understood that all of the front and rear wheel assemblies 20and 22 must be adjusted to the same angular orientation relative to thelongitudinal centerline 26 of the frame 18. The transverse slot 16 cutby the slotting means 24 then has the same angular orientation relativeto a perpendicular to the edges of the pavement strip 14. Preferably, anangular orientation for the front and rear wheel assemblies 20 and 22corresponding to one of the angles a and b is used, rather than an anglewhich would produce a perpendicular slot. However, a slot perpendicularto the longitudinal edges of the pavement strip 14 may be used ifdesired or required.

In the particular construction illustrated, each front wheel assembly 20includes dual front wheels 102 and each rear wheel assembly 24 includesdual rear wheels 104. However, it will be understood that the number ofwheels in each wheel assembly may be increased or decreased if desired.

The wheels of one of the pairs of wheel assemblies 20 and 22, andpreferably the wheels 104 of the rear wheel assemblies 22, are drivingwheels for moving the vehicle 12 along the pavement strip 14 from onejoint location to the next after cutting a transverse slot 16 at thepreceding joint location. An exemplary driving means for the rear wheels104 is designated generally by the numeral 106.

The driving means 106 is shown as including a differential 108,containing conventional ditferential gearing, mounted on the frame 18and having driving connections 110 to the respective dual rear wheels104. The differential 108 may be driven by a hydraulic motor 112supplied with hydraulic fiuid under pressure by a hydraulic pump, notshown, driven by one of the engines 40. (It will be noted that therotary slotting elements 46 are not in operation during forward movementof the wheeled vehicle 12. Consequently, the output of one of theengines 40 may be used to produce the desired forward movement of thevehicle 12). Each driving connection 110 includes a shaft 114 carried bythe corresponding rear wheel assembly 22 and carrying a sprocket 116driving a chain 118 trained around a sprocket 120 on an axle 122carrying the corresponding dual rear wheels 104. The shafts 114 of therespective rear wheel assemblies 22 are connected to opposite sides ofthe differential 108 through shafts 124 and 126, universal joints 128and 130, and slip joints 132, FIG. 3. Such combinations of universal andslip joints permit the hereinbefore-discussed pivoting of the rear wheelassemblies 22 relative to the frame 18.

The driving connections 110 between the differential 108 and the twosets of rear wheels 104 incorporate braking devices 136, which may behydraulically operated in a manner not specifically shown, but wellknown in the art. The respective braking devices 136 are controlled byfoot pedals 1'38 accessible from a drivers seat 140, from which acontrol console 142 for operating various other components of themachine 10 is also accessible. taneously while making one of thetransverse cuts 16, the machine 10 may be held absolutely stationary toinsure an accurate cut and to prevent damage to the rotary slottingelements 46. During forward movement of the machine 10 from one slottinglocation to the next, any steering of the machine which may be requiredmay be accomplished by actuating one or the other of the braking devices136.

It is thought that the over-all operation of the pavement slottingmachine 10 of the invention will be clear from the foregoing.Consequently, a further description is not necessary.

Although an exemplary embodiment of the invention has been disclosedherein for purposes of illustration, it will be understood that variouschanges, modifications and substitutions may be incorporated in suchembodiment without departing from the spirit of the invention as definedby the claim which follows:

I claim:

In a machine for transversely slotting a strip of pavement, thecombination of:

(a) a wheeled vehicle movable longitudinally of the strip of pavementand including a frame supported by at least three wheel assemblies twoof which are spaced apart laterally of said vehicle and are spacedlongitudinally of said vehicle from the third wheel assembly;

(b) pavement slotting means, carried by said frame between said frontand rear wheel assemblies and movable laterally of said frame along atransverse slotting path, for transversely slotting the strip ofpavement while said vehicle is stationary;

(c) said wheel assemblies being pivotable relative to said frame aboutupright axes to vary the angle of said transverse slotting path relativeto the path of said vehicle;

(d) said laterally spaced wheel assemblies including driving wheels;

(e) means for driving said driving wheels, including a differential onsaid frame between said laterally spaced wheel assemblies, and includingdriving connections between said differential and said driving wheels;and

(f) said driving connections including universal and slip joints topermit pivoting of said laterally spaced wheel assemblies relative tosaid frame.

References Cited by the Examiner UNITED STATES PATENTS 2,311,891 2/1943Tyson 299-39 2,791,412 5/1957 Hatcher 29939 2,845,851 8/1958 Nagin 29939X ERNEST R. PURSER, Primary Examiner,

By applying the braking devices 136 simul-.

